Mercury switch



@su 4p E953 A, s, DYSART 2,57%@53 MERCURY SWITCH Filed May 22, 1945 3SheGS-Sheel. l

A. S. DYSART MERCURY SWITCH Dec. 4, 1951 3 Sheets-Sheet 2 Filed May 22,1945 Filed May 22, 1945 FICELQ A. DYSART E MERCURY SWITCH 3Sheecs-Shee't 5 FIGLIO INVENTOR ARTHUR S. DYSAFZT ATTOIQ NEY PatentedDec. 4, 1951 MERCURY SWITCH Arthur S. Dysart, Elizabeth, N. J., assignerof one-half to Mabel S. Dysart, Elizabeth, N. J.

Application May 22, 1945, Serial No. 595,155

8 Claims.

Ibis invention relates to mercury switches and particularly to switchesof this type operated by variations in the pressure of a gas iilledchamber forming part of the switch to move a quantity of mercury betweencontact closing and opening positions.

More particularly the invention relates to mercury switches in which asmall quantity of kmercury is forced through an orice or along a channelinto a position to electrically connect two terminals, movement of themercury being effected by heating a chamber, closed except for theoriiice, so that the air or gas within the chamber, being increased involume by being heated, will force the mercury through the orifice intoanother chamber or 'portion of the switch to connect the terminals of yamain or load circuit.

Any gas that will not combine with mercury may be used.

A primary object of the invention is to provide a pressure or heatoperated mercury switch that will be simple, compact, and that will noteasily get out of order.

A feature that enables the above object to be accomplished is that'theparts employed in the switch are few in number and easily assembled inpermanent relative positions within a sealed member.

With the above and other objects in view the invention includes thefeatures of construction and operation set forth in the followingspeciiication and illustrated in the accompanying drawings.

In the accompanying drawings annexed hereto and forming a part or" thisspecification, I have shown the invention embodied in several ldiiierenttypes of liquid contactor switches, but it will be understood that theinvention can be otherwise embodied and that the drawings are not to beconstrued as defining or limiting the scope vof the invention, theclaims appended to this speciiication being relied upon for thatpurpose.

In the drawings:

Figures 1, 3, 4, 5, 7, 9 and l0 are central` longitudinal sectionalviews of mercury switches showing diiierent embodiments of theinvention.

Fig. 2 is a transverse sectional view of one form of the invention takenon the plane of line 2 2 in Fig. 1.

Fig. 6 is a transverse sectional view of .another form of the inventiontaken on the plane of line E-IS in Fig.

Fig. 8 is a transverse sectional View of another form of the inventiontaken on the lplane of line 8 8 in Fig. '7.

Fig. 11 is a transverse sectional view taken on the plane of line Ii-iiin Fig. 10.

In the above-mentioned drawings there have been shown a .number ofdifferent embodiments of the invention which are now deemed :preferableior different conditions and services, but

(Cl. 20D- 122) it is to be understood that changes and modiiications maybe made within the scope of the appended claims without departing fromthe spirit of the invention.

Brieiiy, and in its preferred aspect, the invention may include thefollowing principal parts: First, adjacent chambers communicating witheach other by means of a connecting orice or channel; second, a quantityof mercury movable from one chamber partially or wholly into the other;third, terminals mounted on each of the casings of the chambers; andfourth, means to heat or otherwise change the pressure of the gas in oneor both chambers.

Referring more in detail to the gures of the drawings, and rst to theembodiment of the invention shown in Figs. 1 and 2, it will be seen thattwo metal casings I0 and I2 t partially one within the other and areheld in their relative positions by insulating material such as rubberIii, etc. Surrounding a portion of the inner casing I0 and disposedwithin the inner end of the outer casing I 2 is a channelled member ofporcelain, or other insulating material, forming a rm body member I5. Atthe lowermost part of the inner casing IIJ is a small aperture I8, thebody member I6 being so formed adjacent this orifice I8 that a channelis formed from the interior of the inner casing Ii) to the end wall ofthe outer casing I2. Mercury 20 within the casing Ill may therefore flowthrough the orifice I8 and between the sloping sides of the body memberIt to electrically connect the end walls of the casings I0 and I2 bythis liquid conductor 22. Terminals 22 and 24 on the casings IIJ and I2are electrically connected. when the mercury 20 is forced partially fromthe casing II) and comes into contact with the casing I2.

To force the mercury 2G from the position shown in Fig. 1 into Contactwith the casing I2, a heating resistance 2E is provided within casingI0. When this resistance Zi is connected to a source of current as by aswitch 23 connecting lead lines of a supply circuit, the heat increasesthe pressure and volume of the gas within the chamber of casing iii andforces the mercury 23 partially or wholly from this chamber into Contactwith the end wall of casing I2. This connects terminals 22 and 24electrically and closes the main circuit between terminals 22 and 2li ofany type. Any excess gas will follow the mercury through orifice I8 intospace II without breaking the continuity of the electric circuit. Withthe switch 2B opened the pressure within casing Iii will be reduced bycooling of the gas therein and excess pressure of the gas in the otherchamber ywill return the mercury 29 to the position shown in Fig. 1which will then open the circuit between the terminals 22 and 24.

Terminal screw 25 containsan axial hole 23 communicating with radialhole 2'! near its inner end. Screw 25 is pushed into chamber 9 untilradial hole 21 connects with chamber 9. A rubber tube (not shown) may beattached to the outer end of screw 25 and the switch chambers exhausted.The desired gas is then admitted into the switch through the same tubeat the desired pressure, preferably higher than atmospheric pressure.Nut 3| is then set up tight, drawing the head of screw 25 against plug33, closing the radial hole 21 and sealing the gas into the switch.

Fig. 3 illustrates a modification of the embodiment of the inventionshown in Figs. 1 and 2. Inner and outer casings I and |2, the. bodymember I6 within the outer casing, the terminals 22 and 24, etc., mayall be similar to their corresponding parts shown in Figs. l and 2. In-

stead of the pressure within the inner casing I I6 being increased byheating the gas therein, a bellows 36 is connected thereto as by anipple 32. A hand lever 35 moved about a fixed pivot or axis compressesand expands the bellows 36 and thus increases and decreases the gaspressure within this casing I9 and forces the mercuryl 26 into contactwith the outer casing |2 in the same manner as in Figs. 1 and 2. Atransparent plug I1 provides a window through which the action of theswitch may be seen.

Fig. 4 shows a still further method cf increasing the pressure withinone or the other of the casings I6 or l2 t0 force the mercury 2|! to-make and break an electrical connection between the casings.Surrounding one, or if desired both, of the casings, as in Fig. 4 arejackets 34' and 36 of any suitable material. Each of these jackets isprovided with openings for the entrance and exit of a fluid. The fluidin one of the jackets may be heated or cooled to a different temperaturefrom that in the other s,

jacket, causing a difference in temperature between the casings I0 andl2. When a diiference in temperature exists between the spaces incasings I9 and l2 the mercury 26 `will be forced from one to the otherof its positions in the same manner as in Figs. 1 and 3.

Figs. 5 and 6 show a mercury switch employed as a rheostat tosuccessively by-pass portions of a resistance. Outer and inner shellmembers in the form of metal tubes ||4 and ||6 are provided suitablyinsulated from each other as shown. Enclosed within the outer shell ||6and surrounding the lower part of the inner shell H4 is a porcelain orother body member of heat resisting insulating material H8. This memberI8 connects by a suitable channel or orice with the space within theinner shell H4. Within the body member ||8 a channel |22 is providedwith a plurality of depressions or pools, each pool being successivelyslightly higher and grouped circularly about the inner shell |I4. Alsoeach pool is provided with a contact connected to a point along theturns of a resistance wire |24. By heating the gas within the innershell as by a heating resistance |26, the increased preesure drives aquantity of mercury |28 from the inner shell into the channel |22. Asthe mercury reaches the successive pools, contact is made with differentportions of the resistance coil |24 and successively short circuitsadditional amounts of this resistance. If desired, the connection to theheating coil |26 may include a variable resistance |36 enabling theamount of heat supplied to the heating coil to be controlled to regulatethe time necessary to force the mercury from the inner shellsuccessively into the portions of channel |22 and thus delay thesuccessive short circuitng of the sections of the resistance |24. Asshown in Figs. 5 and 6, a contacter in the form of a vertical metal rod|23 extends into each of the depressions in the channelled member |22,serving to connect this depression with a point on resistance |24.Insulating sleeve |33 and insulating disc |35 are added to preventaccidental contact of parts of opposite polarity.

In Figs. 7 and 8 is shown a mercury oprated switch generally similar tothat shown in Figs. 5 and 6 in that a mercury pool is forced from aninner shell H into channels formed within a body member |32 ofinsulating material and into contact with an outer shell H6. In thisform of the invention, however, the channels in member |32 extendradially t0 enable mercury |28 in any channel to contact the outer shell||6. The space within the inner shell H4 may be heated by a resistancelike resistance |26 contacting the wall of the inner shell, the oppositeend of the resistance being connected to an insulated terminal |34extending through an insulating closure for the inner shell I4. Whentilted in any direction, as by the rolling or pitching of a ship, one ormore channels in member |32 will be maintained filled with mercury andcontact with the outer shell will not be broken. By forming a centraldepression in the insulating body member |32 a quantity of mercury maybe provided within the inner shell and surrounding the opening from theinner shell to maintain this opening sealed without any liability of themercury contacting the cuter shell n until a material amount of mercuryhas been forced from the inner shell.

Fig. 9 shows a double pole switch formed from two single pole switchessimilar to the switch shown in Fig. 3, the two single switches beingoperated by a single bellows. The central bellows |52 when compressedforces gas from the two chambers formed by the inner shells I0 andforces the pools of mercury. 20 at the inner ends of these shellsthrough an orifice and along grooves formed in insulating bodies I6 sothat this mercury 26 will contact the end walls of the outer shells I2.Terminals 22 and 24 are provided on the inner and outer shells i6 and |2respectively, so that when the mercury pools 29 have been forced fromthe inner shells the inner and outer shells of each pair areelectrically connected. Any type of power circuits may be closed bythese simultaneously acting switches.

Figs. 10 and 11 show a form of the invention in which a Siphonconnection is provided through which mercury is forced from inoperativeto operative switch closing position. Two metal tubes |96 and |98, onewithin the other, are supported in position and suitably insulated fromeach other as shown. A channeled block of insulating material 206 isinserted Within the lower end of the outer tube |96, the block having acentral depression and radially extending channels. Extending into thelower end of the inner tube |96 is a Siphon 262, the upper end of whichis within a pool of mercury 264 and the lower end extends partiallywithin the central depression in block 260. A heating resistance 296 isprovided within the upper end of the inner tube |98 so that when the gaswithin the inner tube is increased in pressure by heating thisresistance, or by any other means, mercury 204 will be forced from theinner tube |98 through the siphon 292, which is preferably ofnon-conducting material, into the depression and radial channels withinblock This electrically connects the tubes ld and 93, both of which areprovided with terminals for power circuit. When the gas within tube i99-again cools the reduced pressure therein draws back the mercury 294through the siphon and disconnects the two tubes electrically from eachother. Above the siphon 292 is a diaphragm 298 having a small centralopening therethrough to prevent mercury from entering the upper end or"the tube |98 when the unit is turned to any position.

By means of this type of switch employing a Siphon 292 the switch is notclosed until enough mercury has been forced into the siphon to completethe flow of mercury therethrough. When the flow of mercury through theSiphon starts by the greater weight of mercury in the branch leading tothe lower opening, the flow will continue to f assure completion of theswitch closing action.

What I claim is: 1. A fluid operated switch comprising two electricallyconducting casings filled with a gas, said.

casings being one within the other and normally insulated from eachother, means to change the pressure of said gas within one of saidcasings, a connection between said casings, and conducting iluidnormally retained within one of gas filled casings and movable when thepressure of said gas is changed into a position partially fill ing theother of said casings and electrically con necting terminals secured tosaid casings.

2. A fluid operated switch comprising two metal casings filled with agas, said casings being one within the other and normally insulated fromeach other, means to heat the gas within one of said casings, and aquantity of conducting fluid retained in one of said casings when bothcasings are at the same temperature, some of said fluid being forcedinto the second casing when said first casing is heated, whereby saidcasings are electrically connected when said first casing is heated anda portion of the fluid is forced into the second casing.

3. A fluid operated switch comprising two metal casings one within theother and both casings being lled with a gas and normally insulated fromeach other, means to change the pressure in one of said gas filledcasings, a connection permitting communication between said casings, anda quantity of conducting fluid normally retained within one of said gasfilled casings, said fluid being movable when the pressure of said gasis changed to a position electrically connecting terminals secured tosaid casings.

4. A fluid operated switch comprising 'two metal casings filled with agas, said casings being disposed one within the other and normallyinsulated from each other, means to heat one of said gas filled casings,a connection between said casings, a channelled member of non-conductingmaterial in the other of said casings, and conducting fluid partially insaid channelled member and partially filling one of said gas filledcasings, whereby when said gas in one casing is heated said conductingfluid is forced from said heated casing to said channelled mem ber andinto contact with the other of said casings to electrically connect thetwo casings.

5. 1n a fluid operated switch, two casings filled with a gas, one or"said casings being metal and connected to an electrical terminal, saidcasings being positioned one within the other, means to change thepressure of the gas in one of said casings, a plurality oi switchcontacts, and a conducting :duid normally retained within one of saidcasings, said fluid being forced into the other of said casings andsuccessively into electrical connection with said switch contacts whensaid gas is increased in pressure.

6. A fluid operated switch comprising two casings iilled with a gas, oneof said casings being metal and connected to an electrical terminal,

said casings being positioned one within the other, means to increasethe pressure of gas in one of casings, a member formed of nonconductingmaterial inserted between said casings and having a channel providedwith a pluralty of depressions, a conducting fluid within said member olnon-conducting material and contacting the metal casing, whereby saidfluid forced successively into said depressions when said gas lsincreased in volume, and individual terminals dipping into saiddepressions whereby when said gas is heated said terminals aresuccessively contacted by said conducting fluid.

7. A iluid operated switch comprising two casings, one within the otherand the inner casing being formed of conducting material, a gas withinaid casings, means to change the pressure of h gas in one of saidcasings, a channelled part .i non-conducting material within the outer if and a quantity of conducting liquid normally within the inner casing,a connection beween said casings whereby when the gas pres- Mure withinthe casing containing the conducting liquid is increased liquid isforced from said inner casing into said channelled part, and electricterminals within said outer casing whereby when liquid is forced intosaid channelled part said liquid successively connects said electricterminals.

8. A fluid operated switch comprising two metal casings one within theother and both casings being filled with a gas, said casings beingnormally insulated from each other, means to change the pressure in oneof said gas filled casings, a connection permitting communicationbetween the lower ends of said casings, a quantity of conducting iluidnormally retained within one of said gas filled casings, said fluidbeing movable when the pressure of said gas is changed to a positionelectrically connecting terminals secured to said casings, and means toretain said fluid within the lower end of said inner casing.

ARTHUR S. DYSART.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 375,403 Waterhouse Dec. 27, 18871,106,907 Wilkinson Aug. 11, 1914 1,596,964 Goodhue Aug. 24, 19261,647,595 Weeks Nov. 1, 1927 1,674,489 Vickery June 19, 1928 2,012,491Agnew Aug. 27, 1935 2,047,902 Eitzen July 14, 1936 2,124,626 MishelevichJuly 26, 1938 FOREIGN PATENTS Number Country Date 20,554 Great Britain1904 621,128 Germany Nov. 1, 1935 664,449 Germany Aug. 27, 1938

